Method for preparing silver halide layers having substantially uniform image contrast

ABSTRACT

Photographic elements are provided which comprise a support having thereon a layer containing silver halide and a photographic image forming coupler, the ratio of coupler to the silver halide varying from area-to-area in the layer, the layer also including a development inhibitor-releasing coupler which is maintained at a constant ratio to the image-forming coupler in all areas of the layer. The development inhibitor-releasing coupler functions to reduce variations in dye image contrast caused by the varying ratio of photographic image-forming coupler to silver halide in the layer. Methods for preparing photographic elements are also provided.

Unite States Patent Reid J. O'Connell;

John H. Van Campen, both of Rochester, N.Y.

Apr. 1, 1968 Jan. 4, 1972 Eastman Kodak Company Rochester, N.Y.

Inventors Appl. No. Filed Patented Assignee METHOD FOR PREPARING SILVER IIALIDE LAYERS HAVING SUBSTANTIALLY UNIFORM IMAGE CONTRAST 7 Claims, No Drawings U.S. Cl 117/34, 96/22, 96/23, 96/74, 96/ 100 Int. Cl G03c 1/00,

G03c l/76 Field of Search 96/100, 9; 1 17/34 [56] References Cited UNITED STATES PATENTS 2,761,791 9/l956 Russell 117/34 2,912,343 11/1959 Collins et al. 117/34 3,148,062 9/1964 Whitmore et al. 96/9 Primary Examiner-J. Travis Brown Attorneys-W. H. J. Kline, .I. R. Frederick and Ogden H.

Webster ABSTRACT: Photographic elements are provided which com- METHOD FOR PREPARING SILVER IIALIDE LAYERS HAVING SUBSTANTIALLY UNIFORM IMAGE CONTRAST This invention relates to novel photographic elements and novel methods for their preparation.

It is well known to provide photographic elements which comprise a support having coated thereon a photographic silver halide emulsion layer which contains color former. When certain methods of coating such emulsions are employed, there tend to be differences in the ratio of silver halide to color coupler in various areas of the photographic element. Such differences in the ratio of silver halide to image-forming coupler results in undesirable variations in the contrast of the photographic element. Variations in contrast can appear within a narrow area of the element, causing undesirable changes in the color balance in a single print prepared therefrom. The variations in ratio of coupler to silver halide can also appear slowly over the length of an emulsion layer. In such cases, differences in contrast are apparent, for example, when different samples are exposed and developed under standard development conditions and compared. Differences in contrast are also apparent when such films are utilized in movies. Such differences in contrast are highly undesirable since they result in photographic materials which are not reproducible and have different characteristics upon development. It therefore appears highly desirable to provide photographic elements and methods for their preparation which are characterized by essentially uniform contrast throughout.

One object of this invention is to provide novel photographic elements and processes.

Another object of this invention is to provide photographic silver halide emulsion layers which have essentially uniform contrast throughout.

A further object of this invention is to provide a novel method for preparing photographic silver halide emulsions containing color former, which emulsions provide substantially uniform contrast.

Still other objects of this invention will be apparent from the disclosure herein and the appended claims.

In accordance with one embodiment of this invention, a photographic element is provided comprising a support having coated thereon a photographic silver halide emulsion layer containing photographic image-forming coupler, the ratio of silver halide to photographic image-forming coupler varying in different areas of said layer, said emulsion layer containing a development inhibitor-releasing coupler, the ratio of development inhibitor-releasing coupler to photographic image-forming coupler being essentially constant throughout the layer. It has been found that such photographic layers exhibit substantially uniform contrast throughout. Similar photographic elements, which do not contain development inhibitor-releasing coupler, exhibit objectionably high variations in contrast from area to area in the layer.

In accordance with another embodiment of this invention, in the method of preparing light-sensitive photographic coatings wherein a photographic image-forming coupler and a photographic silver halide emulsion are separately introduced into a mixing zone, admixed and coated onto a support, and the ratio of photographic image-forming coupler to silver halide varies during the coating operation, the improvement is provided which comprises introducing into said mixing zone a development inhibitor-releasing coupler and maintaining an essentially constant ratio of development inhibitor-releasing coupler to photographic image-forming coupler throughout the coating operation. Such processes result in photographic layers which exhibit substantially uniform contrast throughout.

The process of this invention is conveniently carried out by separately metering a photographic emulsion (which can be separately sensitized) and the combination of photographic image-forming coupler and development inhibitor-releasing coupler (which can be incorporated in a hydrophilic colloid that can also contain other emulsion addenda); mixing the emulsion and coupler combination; and coating the mixture on a support, preferably substantially immediately after mixing as described by Collins et al., in US. Pat. No. 2,912,343. A plurality of such emulsions can have the coupler combination incorporated therein and the resulting emulsion can be coated simultaneously, as described by Russell in US. Pat. No. 2,761,791, issued Sept. 4, 1956, which disclosure is incorporated herein by reference.

The present invention can be practiced with any photographic emulsion-coating process which tends to result in photographic silver halide emulsion layers having varying ratios of silver (or silver halide) to image-forming coupler in various areas of the element. The invention is particularly useful in coating processes of the type wherein a silver halide emulsion (which silver halide emulsion can be spectrally sensitized) has photographic image-forming coupler admixed therewith just before the emulsion is coated onto a support. Such processes are described in detail by Collins et al., in US. Pat. No. 2,912,343, issued Nov. 10, 1959, the disclosure of which is incorporated herein by reference. When such coating processes are utilized, there is a tendency for the emulsion layer resulting therefrom to contain variations in the ratio of silver halide to photographic image-forming coupler. Such variations in the ratio of silver to image-forming coupler occur despite elaborate and sophisticated controls on the flow rates of the silver halide emulsion and the photographic imageforming coupler.

The term photographic image-forming coupler is used herein as a word of art and includes organic compounds which react with oxidized primary aromatic amine-developing agents to form dye images. The photographic image-forming couplers, as well as the development inhibitor-releasing couplers which are utilized in the practice of this invention can embody any photographic coupler radical. Typical useful photographic coupler radicals include the 5pyrazolone coupler radicals, the phenolic (including a-naphthol) coupler radicals, and the open-chain ketomethylene coupler radicals. As is well known in the art, S-pyrazolone coupler radicals are customarily utilized for the formation of magenta dyes; phenolic coupler radicals are generally utilized for the formation of cyan color dyes; and, open-chain ketomethylene coupler radicals are generally utilized in the formation of yellow dyes. The coupling position of such coupler radicals is also well known in the art. The 5pyrazolone coupler radicals couple at the carbon atom in the 4-position thereof; the phenolic coupler radicals couple at the carbon atom in the 4-position (relative to the hydroxyl group); and, the open-chain ketomethylene coupler radicals couple at the carbon atom forming the methylene moiety (e.g.,

denotes the coupling position).

An especially useful class of open-chain ketomethylene coupler radicals are described in Formula 1 below:

Formula I 0 be substituted); and, Y, can have a meaning given below for the image-forming and development inhibitor-releasing couplers utilized herein.

The image-forming and the development inhibitor-releasing couplers utilized in this invention can feature a 5-pyrazolone coupler radical having the following general formula:

Formula ll N=CR6 wherein R R and Y represent substituents of the type used in 5-pyrazolone couplers, for example, R can represent a value given for R R can represent a member selected from the group consisting of an alkyl group, a carbamyl group (which can be substituted), an amino group (which can be substituted with various groups such as one or two alkyl or aryl groups), an amido group, e.g., a benzamido group (which can be substituted), or an alkylamido group (which can besubstituted), and, Y can represent a value given below for the image forming and the development inhibitor-releasing couplers utilized herein.

The photographic image-forming and development inhibitor-releasing couplers employed in the practice of this invention can utilize any suitable phenolic (including alphanaphtholic) coupler radicals, including those described in the structural formula below:

Formula 111 OH Ri2- -Rn 22. 3-(4-ter-amyl-3 '-phenoxybenzoylamino)phenol wherein R R R R and Y can represent a substituent of the type used in phenolic couplers, for example, R and R each can represent a value given for R and in addition can represent a member selected from the group consisting of hydrogen, amino, carbonamido, sulfonamido, sulfamyl, carbamyl, halogen and alkoxy; R and R when taken together, can represent the carbon atoms necessary to complete a benzo group, which benzo group can be substituted with any of the groups given for R and R, and, when taken separately, R and R can each independently represent a value given for R and R and, Y represents a value given below for the imageforming and development inhibitor-releasing couplers utilized herein.

The image-forming couplers which can be utilized in the practice of this invention include the nondiffusible, openchain, S-pyrazolone and phenolic couplers referred to above, such as those couplers represented by Formula I, I] and ill above wherein Y, and Y each represents a group of the type used in colorless image forming couplers, such as hydrogen or a coupling off group, e.g., halogen, such as a chlorine or a fluorine atom; a thiocyano group; an acyloxy group, for example, an alkolyloxy group which can be substituted, or an aryloxy group which can be substituted, or a heterocycloyloxy group which can be substituted; a cyclooxy group including an aryloxy group, e.g., phenoxy, naphthoxy, or a heterocyclooxy group, such as a pyridinyloxy group, a tetrahydropyranyloxy group, a tetrahydroquinolyloxy group, etc., and, an alkoxy group; and, Y can represent any value given for Y and Y except an aryloxy group, and in addition Y can also represent a cycloimido group (tag, a maleimido group, a succinimido group, a l,2-dicarboximido group, a phthalimido group, etc.) when R and R are taken together to form a benzo group. The various groups which Y Y and Y; can represent may include groups such as:

(a)? OX3 wherein R and R have a meaning given for R,, and X and X each have a meaning given for X Especially good results are obtained when the image-forming coupler is colorless; it can, however, be colored if desired. It will be understood that the image-forming couplerdoes not release a development inhibitor.

The useful image-forming couplers include both the 4- equivalent and Z-equivalent nondiffusing couplers. Typical useful 4-equivalent yellow dye-forming couplers which can be utilized in this invention include the following:

1. N-amyl-p benzoylacetaminobenzenesulfonate 2. N-(4-anisolyacetaminobenzenesulfonyl)-N-benzyl-mtoluidine 3. N-( 4-benzoylacetaminobenzenesulfonyl )-N-benzylaniline 4. m-(p-benzoylbenzoyl )acetaniiine 5. w-benzoyl-p-sec-amylacetaniline 6. N,N-di(m-benzoylacetyl )-p-phenylenediamine 7. a-{3 a-( 2,4-di-tert-amylphenoxy)butyramido]-benzoyl}- 2-methoxyacetaniline 8. 4,4'-di-(acetoacetamin0 )-3,3 '-dimethyldiphenyl 9. p,p'-di-(acetoacetamino)diphenylmethane l0. nonyl-p-benzoylacetaminobenzenesulfonate l l N-phenyl-N-(p-acetoacetaminophenyl)urea n-propyl-p-benzoylacetaminobenzenesulfonate acetoacetpiperidide l3. N-(w-benzoylacetybl ,2,3,5-tetrahydroquinoline l4. N-(w-benzoylacetyl)morpholine The 2-equivalent yellow dye-forming couplers can be derived from corresponding parent 4-equivalent couplers by replacing one of the two hydrogens on the alpha-carbon (i.e., methylene) with any nonchromophoric coupling-oil group, in cluding coupling-off groups such as the al., atom, the chlorine atom, an acyloxy group, a cyclooxy group and a thiocyano group. Typically useful Z-equivalent couplers include the alpha-fluoro couplers of US. Pat. No. 3,277,l55, the alpha chloro couplers of US. Pat. No. 2,778,658, the alpha-thiocyano couplers of US. Pat. No. 3,253,924, the alpha-acyloxy couplers of Loria US. patent application Ser, No. 477,353. filed July 26, 1965, the alpha-cyclooxy couplers of Loria U.S. patent application Ser. No. 469,887, filed July 6, 1965, and the alpha-alkoxy couplers of the type shown in Whitmore et al. US. Pat. No. 3,227,550.

Typical useful 2-equivalent yellow-forming openchain ketomethylene couplers include the following:

i. 4-(01-2'-methoxybenzoyl-a-chloroacetamido)-3 4 tert-amylphenoxy)benzanilide 2. a-o-methoxybenzoyla-chloro-4la-(2,4-di-tertamylphenoxy )-n-butyramidoI-acetanilide 3. a-{3-[a-(2,4-di-tert-amylphenoxy)butyramido1benzoyl a-fluoro-2-methoxyacetanilide tyramido]-2-chloroacetanilide tyramido] benzoyl }2-methox yacetanilide 6. a-benzoyl-a-[a-(2,4-di-n-amylphenoxy)acetoxy1-2- methoxyacetanilide 7. a-pivalyl-a-stearoyloxy-4-sulfamylacetanilide 8. a-pivalyl-a-[a-( 3-pentadecylphenoxy )acet0xy1-3 ,5diamyloxyacetanilide a-acetoxy-a- 3-[ u-( 2,4-di-tert-amylphenoxy )butyramidolbenzoyl 2-methoxyacetanilide 10. a-( 3-dodecanamidobe nzoyl )-a-octanoyloxy-2-methoxy-acetanilide l l. a-{-3-[y-(2,4-di-tert-amylphenoxy)butyramidolbenzoyl }-a(4-nitrophenoxy)-2-methoxyacetanilide 1 2. a-[4-(N-methyl-N-octadecylsulfamyl )phenoxy 1-01- pivalyl-4-octylacetanilide potassium salt l3. a-pivalyl-a-(4-sulfophenoxy-4-(N-methyl-N-octadecylsulfamyl)acetanilide potassium salt 14, a-[4-(4-hydroxyphenylsulfonyl)phenoxy]-a-pivaly|- 2-chloro-5-[y-(2,4-di-tert-amylphenoxy)butyramido lacetanilide l5. 4,4'-bis[a-pivalyl-a- 2-chloro-5-[ -(2,4-di-tertamylphenoxy)butyramido]phenylcarbamyl methoxy]- diphenylsulfone l6. a-benzoyl-a-thiocyanoacetanilide Specific representative 4-equivalent magenta dye-forming couplers include can be used in this invention include the following:

]. 1-psec-amylphenyl-3-n-arnyl-5-pyrazolone 2. Z-cyanoacetyl-S-(p-sec-amylbenzoylamino)coumarone 3. 2-cyanoacetylcoumarone-5-(N-n-amyl-p-tert-amylsulfanilide) 4. 2-cyanoacetylcoumarone-5-sulfon-N-n-butylanilide 5. 2-cyanoacetyl-5-benzoylamino-coumarone 6. 2-cyan0acetylcoumarone-5-sulfondimethylamide 7. 2-cyanoacetylcoumarone-5-sulfon-N-methylanilide 8. 2-cyanoacetylcoumarone-5-(N-y-phenylpropyD-p-tertamylsulfonanilide 9. l-p-laurylphenyl-3-methyl-5-pyrazolone l0. l'B-naphthyl-3-amyl-5-pyrazolone 1-p-nitrophenyl-3-n-amyl-5-pyrazolone l-p-phenoxyphenyl-3-n-amyl-5-pyrazolone l-phenyl-3-n-amyl-5 -pyrazolone l4. 1,4-phenylene bis-3-( l-phenyl-5-pyrazolone) l5. 1-phenyl-3-acetylamino-5-pyrazolone 1-phenyl-3-n-valerylamino-5-pyrazolone 1-phenyl-3-chloroacetylamino-5-pyrazolone 1-phenyl-3-benzoylamino-5-pyrazolone 1-phenyl-3-(m-aminobenzoyl)amino-S-pyrazolone 1-phenyl-3(p-sec-amylbenzoylamino)-5-pyraz0lone l-phenyl3-diamylbenzoylamino-S-pyrazolone l-phenyl-3-B-naphthoylamino-5-pyrazolone l-phenyl-3-phenylcarbamylamino-5-pyrazolone l-phenyl-3-palmitylamino-5-pyrazolone l-phenyl-3-benzenesulfonylamino-5-pyrazolone 26. l-(p-phenoxyphenyl)-3-(p-tert-amyloxybenzoyl)amino- 5-pyrazolone 27. l-(2',4, 6-trichlorophenyl)-3-benzamido-5-pyrazolone 28. l-(2, 4', 6-tribromophenyl)-3-phenylacetamido-5- pyrazolone 29. l-(2,4'-dichlorophenyl)-3-[3-(2",4"di-tertamylphenoxyacetamido)benzamidoih-S-pyrazolone 30. l-(2', ,6-trichlorophenyl)-3-[3"-(2"', 4-di-tertamylphenoxyacetamido)benzamido-5-pyrazolone 3 l. l-(2, ,6-trichlrophenyl)-3-[B-b 2", "-di-tertamylphen0xy)-propionamid0l-5-pyrazolone 32. l-( 2 -dichlor0)-3-[ 3 4 'tert-amylphenoxy)benzamido]--pyrazolone 33. l-(2, -tribr0m0phenyl)-3-[3"-(4'-tert-amylphenoxy)-benzamidol-5-pyrazolone 34. l-(2, -dichlorophenyl)-3-[3-(2, 4"-di-tertamylphenoxyacetamido)benzamidoih-S-pyrazolone The 2-equivalent S-pyrazolone couplers can be derived from the parent 4-equivalent S-pyrazolone couplers by replacing one of the hydrogens on the carbon in the 4-position of the pyrazolone ring with a nonchromophoric couplingoff group. Examples of coupling-off groups which can be used in 2- equivalent magenta-forming S-pyrazolone couplers are the thiocyano group illustrated by the couplers in Loria U.S. Pat. No. 3,252,924 and the acyloxy group containing 2equivalent magenta-forming couplers of Loria U.S. Pat. No. 3,311,476. Other useful coupling-off groups include acyloxy, aryloxy, alkoxy such as any of those shown in Whitmore et al., U.S. Pat. No. 3,227,550, the chlorine atom, the fluorine atom, and the sulfo group.

Typical 2equivalent magenta dye-forming couplers which can be used in this invention include the following:

1. l( 2,4,6-trichl0rophenyl )-3-(4-nitroanilino )-4- stearoyloxy-S-pyrazolone l-(2,4,6-trichlorophenyl)-3-{3-[a-(2,4-di-tertamylphenoxy)-acetamido]benzamido}-4-acetoxy-5- pyrazolone 3. l-(2,4,6-trichlorophenyl)-3-pentadecyl-4-thiocyano-5- pyrazolone 4. l-(2,4,6-trichlorophenyl)-3[3-(2,4-di-tert-amylphcnoxyacetaido)benzamido]-4-thiocyano-5-pyrazolone 5. l-( p-tert-butylphenoxyphenyl )-3-cx l p-tert-butylphenoxyphenyl)-3-a-(p-tert-butyl-phenoxy)- 5 propionamido-4-thiocyano-S-pyrazolone 6. l-(2,4,6-trichlorophenyl-3-pentadecyl-4-sulfo-5- pyrazolone 7. l-(2,4,6-trichlorophenyl )-3-pentadecyl-4-chloro-5- pyrazolone 8. l-[4-( 3,5-dimethoxylbenzamido)phenyl]-3 eth0xy-4-( 3- octadecylcarbamylphenylthio)-5-pyrazolone Typical 4-equivalent cyan-forming phenolic couplers which can be used in this invention include:

. 5-(p-amylphenoxybenzenesulfonamino l -naphthol 2. 5-(n-benzyl-N-n-valerylamino)-l-naphthol 3. S-caproylaminol -naphthol 4 2-chloro 5-(N-n-valeryl-N-p-isopropylbenzylamino)- lnaphthol 2-chloro-5-palmitylaminol -naphthol 5-diphenylethersulfonamidol-hyroxy-2-(N-isoamyl-N-phenyl)naphthamide 8-hydroxy-l-a-naphthoyl-l ,2,3,4-tetrahydroquinoline l-naphthol-5-octyl-cyclomexylamide l0. 5-phenoxyacetaminol -naphthol l l. Monochlor-5-(N-y-phenylpropyl-N-psec-amylbenzoylamino l -nanphthol 12. 2-benzoylamino-3,S-dimethyphenol l3. 2-a-(p-tert-amylphenoxy)-nbutyrylamino-5- methylphenol l4. l-hydroxy-N-[o-( 2,4-di-tert-amylphenoxy )butyl ]2- naphthamide l5. 2-(4-tert-amyl-3-phenoxybenzoylamino)-3,5-

dimethylphenol 16, 2(4-tert.-amyl-3-phenoxybenzoylamino)phenol l7. 2-[aa(-4'-tert.-butylphenoxy)propionylamino4lphenol l8. 2-[N-methyl-N(4'-tert-amy|-3-phenoxybenzolyaminO)]Phenol l9. 2-60 (4tert-amylphenoxy)butyrylaminol -phenol 20. 2-(4-tert-amyl-3-phen0xybenzoylamino)3,5-

dimethylphenol 21. 2[ a-(4tert-amylphenoxy )-nbutyrylamino ]-5- methylphenol 22. 3-(4-tert-amyl-3phenoxybenzoylamino)phenol 23. 2-[aa-(4-tert-amylphenoxy)-n-butyrylamino1-6- chlorophenol 24. 3-[a-(4-terL-amylphenoxy)-n-butyrylamino]-5- chlorophenol 25. 5-benzene sulfonamido-l-naphthol 26. 2-chloro-5-benzenesulfonamido' l -naphthol 27. 5-( l,2,3,4-tetrahydronaphthalene-6-sulfonamido lnaphthol 28. 2-chloro-5-( 4brom0diphenyl-4-sulfonamido) l -napthol Any of the 2-equivalent cyan-forming phenolic couplers can be used in the practice of this invention. The 2-equivalent phenolic, couplers can be derived from the corresponding 4- equivalent phenolic couplers by substituting a nonchromophoric coupling-off group on the carbon in the 4- position of the phenolic or naphthoic ring. Included among the coupling-off groups are the acyloxy group illustrated by the 4-acyloxyphenols and 4acyloxynaphthols of Loria U.S. Pat. No. 3,31 1,476, issued Mar. 28, 1967, the cyclooxy group illustrated by the 4-cyclooxy naphthols of Loria U.S. patent application Ser. No. 483,807, filed Aug. 30, 1965, the thiocyano group illustrated by the 4-thiophenols and 4- thionaphthols of Loria U.S. Pat. No. 3,253,294, the cyclic imido groups as illustrated by the 4-cyclic imido derivatives of l-hydrogen-2-naphthamides of Loria U.S. patent application Ser. No. 504,994, the chlorine atom as illustrated in the 4- chlorophenols of Weissberger U.S. Pat. No. 2,423,730, the alkoxy group as illustrated by the 4-alkoxynaphthols (and naphthols) of Whitmore et al. U.S. Pat. No. 3,227,550, the sulfo group as in 4-sulfophenols and 4sulfonaphthols, etc.

Typical 2-equivalent cyan-forming couplers which can be used in this invention include the following:

l l-hydroxy-4-decyloxy-2-naphthamide 2. 1-hydroxy-4-acetxy-N-[a-( 2,4-di-tert-amylphenoxy)butyl ]-2-naphthamide 3. l-hydroxy-4-methoxy-N-octadecyl-3 ,5 '-dicarboxy-2- naphthanilide 4. l-hydroxy-4-thiocyano-N-[11-2,4-di-tert-amylphenoxy)- butyl 1-2-naphthamide 5. l-hydroxy-4-( pentafluorophenoxy)-N-{ {-4[ B-( 2,4-ditert-amylphenoxy )acetanudo]phenyl}ethyl} -2-naphthamide 6. 1-hydroxy-4-(4-nitrophenoxy )-N-[ aa-2,4-di-tertamylphenoxy)butyll-2-naphthamide 7. l -hydroxy-4-( 4-chlorophenoxy-2 -tetradecyloxy- 2- naphthanilide The photographic image-forming coupler is used at a sufficient concentration to give a dye image of suitable density. The concentration employed will depend on the characteristics of the dye formed by the coupler, and on the nature of the photographic emulsion in which it is incorporated. The photographic image-forming coupler preferably is nondifi'usible, and colorless. It can be a coupler of the type which forms a diffusible dye image (which can be transferred to a suitable receiving sheet) or a type which forms nondiffusible dye images. The invention is useful with all photographic incorporated image-forming couplers which form dye images by imagewise reaction with oxidized primary aromatic amine color-developing agent. Incorporated refers to silver halide emulsion layers containing photographic image-forming couplers at the time of exposure.

The term development inhibitor-releasing coupler is used herein as a word of art to refer to those photographic couplers which, upon reaction with oxidized primary aromatic amine color-developing agent, form dye and release a compound which inhibits development. Development inhibitor-releasing (DlR) couplers which can be utilized herein can be represented by the general formula:

ZC,. wherein C represents a photographic coupler radical, preferably an open-chain ketomethylene, S-pyrazolone or phenolic (including alpha-naphtholic) coupler radicals, having said Z substituted in the coupling position of the coupler radical, Z representing an organic group which does not contain a chromophore, does not couple with oxidized primary aromatic amine color developer to form dye, does not inhibit development while attached to Cp, but is released from C on reaction with oxidized primary aromatic amine color develop ing agent, and either is or forms a compound which inhibits development. Especially useful DIR couplers have formula I, ll or Ill above, wherein, Y Y and Y each are selected from:

1. a monothio group, such as, ortho-nitro or ortho-amino substituted arylmonothio groups (such as, 2 -nitrophenyl and 2-aminophenyl), a carbon containing heterocyclic monothio group (generally having a 5 to 6-membered ring containing at least one heteronitrogen, oxygen or sulfur atom and preferably one to four heteronitrogen atoms) including heterocyclic radicals, such as, tetrazolyls, triazinyls, triazolyls, oxazolyls, oxadiazolyls, diazolyls, thiazyls, thiadiazolyls, benzoxazolyls, benzothiazolyls, pyrimidyls, pyridinyl, quinolinyls, etc., and in which the aryl-, heterocyclic moieties of the monothio group are either unsubstituted or substituted with various groups, such as nitro, halogen (chlorine, bromine, iodine, fluorine), lower alkyl, lower alkylamido, lower alkoxy, lower alkylsulfonamido, achloroacetylthio, lower alkylcarbamyl amino, etc., typical monothio groups representing the above include 2- aminophenyl, 2-nitrophenyl and a heterocyclic group (e.g., Z-benzo thiazolylthio, l-phenyl-5-tetrazolythio, l- (4-carbonmethoxyphenyl)-5-tetrazolythio, 5-phenyll ,3,4-oxadiazolyl-2-thio, 2-phenyl-5-( 1,3 ,4)-oxadiazolythio, Z-benzoxazolythio, etc.); 2. a Z-aminoarylazoxy group (e.g., 2-amino-4-methylphenylazoxy, 2-aminophenylazoxy, 2-amino-4-chlorophenylazoxy, etc.

3. a 2-amidoarylazoxy group (e.g., Z-acetamidophenylazoxy, 2-acetamido-4-rnethylphenylazoxy, 2-acetamido-4- chlorophenylazoxy, Z-palmitamidophenylazoxy, 4- methoxy-Z-palmitamidophenylazoxy, 4-chloro-2-pal mitamidopehnylazoxy, etc.

4. a Z-aryltriazolyl group (e.g., 2-benzotriazolyl, 5-chloro-2- benzotriazolyl, 5-hydroxy-2-benzotriazolyl, 4,7-dinitro-2- benzotriazolyl, 5 -methyl-2-benzotriazolyl, 6-methoxy-2- benzotriazolyl, 4-carboxyethyl-4-sulfoethyl-2- benzotriazolyl, Z-naphthotriazolyl, 4-methyl-2 naphthotriazolyl, 5-chloro-Z-naphthotriazoyl 5-hydroxy- 2-naphthotriazolyl, 5-nitro-2 -naphthotriazolyl 5-sulfoethyl-2-naphthotriazolyl, 4-amino-2-naphthotriazolyl, benzo[ l,2-d:4,5-d]-bristriazolyl, etc.

The Z group (or Y Y and Y in the above formulas) l forms a diffusible mercaptan and (2), (3) and (4) form a diffusible aryltriazole upon reaction with oxidized color developing agent.

Representative DIR couplers include the following:

1. a-Benzoyl-a-( 2-nitrophenylthio )-4-[ N-( y-phenylpropyl N-(p-tolyl )-sulfamyl ]acetanilide 2. a-Benzoyl-x-( Z-benzothiazolylthio )-4-[ N-( 'y-phenylpropyl )-N-( p-tolyl )sulfamyl ]acetanilide 3. a-{ 3-[a-(2,4-di-tert-amylphenoxy)butyramido1-benzoyl} -a-2nitrophenylthio-2-methoxyacetanilide 4. a-{ 3'y-( 2,4-di-tert-amylphenoxy )butyramido -benzoyl} a-( 2-benzoxazolylthio )-2-methoxyacetanilide 5. a-Benzoyl-a-[ l-( 3-phen yl )-5 -tetrazolythio lstearamido stearamido acetanilide 6. a-{3-[a-(2,4-di-tert-amylphenoxy)butyramido]benzoyl a-( 2-aminophenylazoxy )-2-methoxyacetanilide 7. a- {3-[y-( 2,4-di-tert-amylphenoxy )butyramido ]-benzoyl} a-( 2-amino-4-methylphenylazoxy)-2-methoxyacetanilide 8. a( 5-Chlor0-2-benzotriazolyl )-a-pivalyl-5-[ a-( 2,4-ditert-amylphenoxy)propylamido]-2-chloroacetanilide 9. a-( 4,7-Dinitro-2-benzotriazolyl )-a-pivalyl-3 ,-dichloro- 4-( N-methyl-N-octadecylsulfamyl )acetoacetanilide 10. a-( 6-Chloro-5 methoxy-2-benzotriazolyl )oz-pivalyl-Z- chloro5-[ -pivalyl-.LOROb 5 a(3-pentadecyl-4-sulfophenoxoy )-butyramido]acetanilide, sodium salt l l. l-Phenyl-3-octadecylamino-4-[ 2-phenyl-5 l ,3,4 )-oxadiazolylthiol-S-pyrazolone l2. l-{4-[-y-(2,4-di-tert-amylphenoxy)butyramido1phenyl}- 3-ethoxy-4-( l-phenyl-S-tetrazolylthio )-5-pyrazolone l3. 1- 4-[a-( 3-pentadecylphenoxy )buty ramido ]phenyl }-3 ethoxy-4-( l-phenyl-5-tetrazolylthio )5pyrazolone l 4. l-( 2,4,6-trichlorophenyl )-3 4- a-(2 ,4-di-te rtamylphenoxy )butyramidolanilino }-4-( l-phenyl-5- tetrazolythio )-5 -pyrazolone l5. l -Phenyl-3-octadecylamino-4-( l-phenyl-S- tetrazolylthio )-5-pyrazo|one l 6. l 4-(4-tert-butylphenoxy)phenyl1-3 -phenyl-4-( l -phenyl-5-tetrazolylthio )-5-pyrazolone l7. 1 -[4-(4-tert-butylphenoxy)phenyl1-3-[a44-tert-butylphenoxy )propionamido ]-4-( 5-phenyl-l ,3 ,4-oxadiazolyl-2-thio)-5-pyrazolone 18. l 4-( 4-tert-butyl phenoxy)phenyl }-3- u-(4-tert-butylphenoxy )propionamido ]-4-( 2-nitrophenylthio )-5- pyrazolone 19. l-[ 4-( 4-tert-butylphenoxy )phenyl ]-3-[ a-(4-tert-butylphenoxy )propionamido ]-4-[ l-(4-methoxyphenyl )-5- tetrazolylthio1-5 -pyrazolone 20. l [4-(4tert-butylphenoxy)phenyl1-3-[a-(4-tert-butylphenoxy )propionamido ]4-( Z-benzothiazolylthio )-5 pyrazolone 21. 1-[ 4-(4-tert-butylphenoxy )phenyl]-3-[ a-( 4-tert-butylphenoxy)propionamido1-4-(2-nitrophenylthio)-5- pyrazolone 22. l-[ 4-(4-tert-butylphenoxy )phenyl 1-34 a-( tert-butylphenoxy )propionamido ]-4-( 2-benzoxazolylthio)-5- pyrazolone 23. l 2 ,4-dichloro--methoxyphenyl )-3-[ a-( 3-pentadecylphenoxy )acetamido }-4-( l-phenyl-S- tetrazolylthio )-5-pyrazolone 24. 1-Phenyl-3-octadecyl-4-( l-phenyl--tetrazolythio)- 25. 1-Phenyl-3-[a-(2,4-di-tert-amylphenoxy)acetamido]-4 1-phenyl-5-tetrazolylthio)-5-pyrazolone 26. 1-Phenyl-3-[y-(2,4-di-tert-amylphenoxy)butyramido]- 4-( 1-phenyl-5-tetrazolylthio-5-pyrazolone 27. l-Phenyl-3-(3,5-didodecyloxybenzamido)-4-(2- nitrophenylthio )5-pyrazolone 28. l-Phenyl-3-[a-(2,4-di-tert-amylphenoxy)acetamido]-4- (2-aminophenylazoxy)-5-pyrazolone 29. 4-Benzotriazolyl-3-pentadecyl-1-phenyl-5-pyrazolone 30. 4-Benzotriazolyl-1-(2,4,6-trichlorophenyl)-3-[3-{a- (2,4-di-t-amylphenoxy)acetamido 3- a-(2,4-di-tamylphenoxy)acetamido} benzamido]-5-pyrazolone 31. 4-(5-Methoxy-2benzotriazolyl)-3-pentadecyll phenyl- S-pyrazolone 32. 4-( 4-Carboxy-2-benzotriazolyl l -(2 ,4,6-trichlorophenyl)-3-pentacecyl-5-pyrazolone 33. l-l-lydroxy-4-(Z-nitrophenylthio)N-[8-(2,4-di-tertamylphenoxy)butyl]-2-naphthamide 34. 1-Hydroxy-4-(2-benzothiazolylthio)N-[8(2,4-di-tertamylphenoxy)butyl]-2-naphthamide 35. 1-Hydroxy-4-(1-phenyl-5-tetrazolythio)-N-[8(2,4-ditert-amylphenoxy)butyll-2-naphthamide 36. l-Hydroxy-4-(2-benzothiazolylthio)-N-octadecyl-3,5'-

dicarboxy-2-naphthanilide 37. 1-Hydroxy-4-( l-phenyl-5-tetrazolythio)-2 tetradecyloxy-2-naphthanilide 38. 1-l-lydroxy-4-[1-(4-methoxyphenyl)-5-tetrazolylthio]- N-[8(2,4-di-tert-amylphenoxy)butyl-2-naphthamide 39. l-Hydroxy-4-( 5-phenyll ,3,4,-oxadiazolyl-2-thio)-N-[6 (2,4-di-tert-amylphenoxy )butyl -2-naphthamide 40. 5-Methoxy-2[a-(3-n-pentadecylphenoxy)butramido] 4-( 1-phenyl-5-tetrazolylthio)phenol 41. 1-Hydroxy-4-(2-amino-4methylphenylazoxy-N-[ 8-( 2,4-di-tert-amylphenoxy)butyl]-2-naphthamide 42. 4-(2Benzotriazolyl)-2-[8-(2,4-diarnylphenoxybutyl)1- l-hydroxynaphthamide 43. 1-Hydroxy-4-( 6-nitro-2-benzotriazolyl )-N 8'( 2,4-di-tamylphenoxy)butyl]-2-naphthamide 44. 5-Methoxy-2-[a-(3-pentadecylphenoxy)butyramidoj-4- (5-chloro-2-benzotriazolyl )phenol -45. 5-Methoxy-2-[a-( 3-pentadecylphenoxy)butyramido]-4- (6-chloro-5-methoxy-2-benzotriazoly )phenol Couplers 1 through 5, 11 through 27, 33 through 40 are described in Barr, U.S. Pat. No. 3,227,554. Couplers 6, 7, 28 and 41 are prepared by methods similar to those disclosed in U.S. Pat. No. 3,148,06. Couplers 8 through 10, 29 through 32 and 42 through 45 are described by Sawdey, U.S. Pat. application Ser. No. 674,090, filed Oct. 10, 1967. The couplers referred to in the immediate paragraph are the DlR couplers listed above.

The most useful DIR couplers are those which have a monothio group in the coupling position (e.g., formula 1, II and 111 above in which Y,, Y and Y represent a monothio group). Preferred DIR couplers have formula I, 11 or 111 above wherein Y Y and Y each represents a heterocyclic monothio radical in which the heterocyclic ring has from five to six atoms and at least one hetero atom selected from oxygen, sulfur and nitrogen, such as a hetero ring, containing from one to four hetero nitrogen atoms, e.g., a S-tetrazolylthio group. Preferably, a DIR coupler is selected which forms a dye of substantially the same color as the dye formed by the image-forming coupler.

The development inhibitor-releasing coupler is utilized at a concentration sufficient to effectively provide substantially uniform contrast in the emulsion layer. The most useful concentration will depend upon how much variation there is in the ratio of silver halide to photographic image-forming coupler, as well as on the nature of the particular development inhibitor-releasing coupler selected. As a general guide, the most useful results are achieved using a ratio of from 2 to 25 parts by weight development inhibitor-releasing coupler per 100 parts by weight photographic image-forming coupler.

The photographic image-forming coupler and the development inhibitor-releasing coupler utilized in the photographic emulsions and processes of this invention preferably are nondiffusible. The term nondiffusible" as used herein has the meaning commonly applied to that term in color photography, and denotes materials which for all practical purposes do not migrate or wander through photographic hydrophilic colloid layers, such as gelatin, particularly during processing in aqueous alkaline solutions. The term diffusible has the converse meaning.

Preferably, the image-forming and the development inhibitor-releasing couplers utilized herein are ballasted. That is, the coupler contains an organic radical of such molecular size and configuration as to render the coupler nondiffusible in the element and when the element is processed in alkaline-developing solutions. The organic ballasting radical is chosen so that it does not exercise any detrimental effects on the photographic material.

The image-forming and development inhibitor-releasing couplers utilized in this invention can be incorporated into the silver halide emulsion in any convenient manner. For example, the coupler can contain a solubilizing group, such as a sulfonic acid group or a carboxylic acid group, such the couplers soluble in alkaline solution. This enables incorporation of the coupler into the silver halide emulsion by preparing an aqueous alkaline solution of coupler and mixing that solution directly into the photographic silver halide emulsion. Preferably, the couplers are incorporated into the emulsion by dissolving them in a suitable coupler solvent, for example, one of the color coupler solvents and utilizing one of the processes described in U.S. Pat. Nos. 2,322,027 and 2,801,171.

in addition to image-forming couplers and development inhibitor-releasing couplers, the photographic emulsions of this invention can contain a competing coupler, which can be introduced prior to coating the emulsion or during development thereof. The competing coupler can be one which forms a leuco dye or a diffusible dye. Typical useful competing couplers are described by Loria, Williams and Barr in British Pat. No. 1.038,33l; Wellar and Greet in U.S. Pat. No. 2,689,793, and U.S. Pat. No. 2,998,314.

Emulsion layers can be produced in accordance with this invention which contain colored couplers, e. g., those which contain an azo group in the coupling position. Such couplers are well known in the photographic art. Representative useful azo substituted couplers are described in the following U.S. Pat. Nos: 2,428,054, 2,449,966, 2,453,551 (open-chain ketomethylene couplers having an arylazo group in the coupling position; and couplers in which the arylazo group is replaced with an alkylazo or a heterocycloazo group in the coupling position are also useful); U.S. Pat. No. 2,455,169 (phenolic couplers having an arylazo group in the coupling position; couplers in which a heterocycloazo group replaces the arylazo group are also useful); U.S. Pat. Nos. 2,455,170, 2,521,908, 2,569,418 (S-pyrazolones having an arylazo or heterocycloazo group in the coupling position), U.S. Pat. Nos. 2,706,684, 2,725,292; 2,983,608; 3,005,712; 3,034,892; and, in British Pat. Nos. 800,262 and 1,043,044. Specific useful photographic couplers can be selected from the disclosure of the foregoing references which are incorporated herein by reference. Such couplers can be utilized in the manner known in the art to correct or mask unwanted absorption of the dye formed by the image-forming coupler.

As used herein, blue radiation refers to radiation of from about 400 to 500 nm.; green" refers to radiation of from about 500 to 600 nm.; and, red refers to radiation of from about 600 to 700 nm. Preferably, the cyan dyes formed by the colorless coupler has its major absorption between about 600 and 680 nm.; the magenta dye between about 500 and 580 nm.; and the yellow dye between about 400 and 480 nm.

in preparing silver halide emulsions or dispersions used in the photographic elements of the invention a wide variety of organic hydrophilic-dispersing agents or substrates for the silver halide can be utilized. Gelatin is preferred although other colloidal materials such as colloidal albumin, cellulose derivatives or synthetic resins such as polyvinyl alcohol can also be utilized.

in preparing the photographic elements of the invention, silver halide emulsions can be coated on a wide variety of photographic supports. Typical supports include cellulose nitrate film, cellulose acetate film, polyvinyl acetal film, polystyrene film, polyterephthalate film, polyethylene film,

polypropylene film, polyethylene-coated paper, paper, glass and others.

The photographic silver halide emulsions and other layers on the present photographic elements can contain the addenda generally utilized in such elements including optical sensitizers, speed-increasing materials, antifoggants, coating aids, gelatin hardeners, plasticizers, ultraviolet absorbers and the like.

Gelatin overcoat Blue sensitive silver bromiodide gelatin emulsion containing coupler A+coupler B Yellow filter layer Green sensitive silver bromoiodide gelatin emulsion-lcoupler C-l-coupler Dl-coupler E Pat. No. 2,80l,l7l.

Coupler A-A yellow dye-forming coupler of the type described in example XIV of McCrossen et al. U.S. Pat. No. 2,875,057

Couple r BA yellow dye-forming DIR-coupler of the type described in Weissberger et al. U.S. Pat. No. 3,265,506 (Compound l3) Coupler CA magenta dyeforming coupler of the type described in Loria et al. US. Pat. No. 2,600,788 (Compound Coupler DA blue-absorbing magenta dye-forming coupler of the type described in Beavers U.S. Pat. No. 2,983,608 (Coupler l) Coupler EA magenta dye-forming DIR-coupler of the type described in Barr et al. US. Pat. No. 3,227,554 (e.g., Compound XXXVll) Coupler FA cyan dye-forming coupler of the type described in Weissberger et al. U.S. Pat. No. 2,474,293 (Compound l) Coupler G-A blue-green-absorbing cyan dye-forming coupler of the type described in Gledhill et al. U.S. Pat. No. 3,034,892 (Compound Il) Coupler HA cyan dye-forming DIR-coupler of the type described in Barr et al. U.S. Pat. No. 3,227,554 (example l4, Compound X1) EXAMPLE 1 A photographic element of the type described above is prepared and coated in which the red sensitive emulsion and the cyan dye-forming coupler dispersion are mixed just prior to coating as described in Collins et al. U.S. Pat. No. 2,9] 2,343. A series of coatings are prepared in which (I the silver coverage/coupler coverage ratio is varied by varying the coupler dispersion flow rate and (2) the nonDIR-coupler/DlR-coupler ratio is varied by coating at a constant flow rate separate coupler dispersion having the appropriate ratios. Samples of each coating are exposed on an intensity scale sensitometer and processed through the Eastman Color Print Process, described in Production of Motion Picture Film and Motion Pictures in Color Using Eastman Color Films," [ll-l5 et seq., published by the Eastman Kodak Company, 1963, at 75 F. and a development time of 8 minutes, with the following results:

Gelatin interlayer Red sensitive silver brornoiodido gelatin emulsion-lcoupler F+coupler G-l-coupler H Cellulose ester film support Two or more of the layers of the photographic element are coated simultaneously as described in Russell U.S. Pat. No.

2,761 ,791. The couplers are dissolved in organic solvents and dispersed in a gelatin solution as described in Fierke et al. U.S.

It can be seen from the above results that when the coverage of the DIR-coupler varies with the image coupler (No. 1-5), substantially uniform contrast is obtained in the layer, although the ratio of silver to coupler varies widely in the same layers.

EXAMPLE 2 A photographic element of the type described above is prepared and coated in which the green-sensitive emulsion and the magenta dye-forming coupler dispersion are mixed just prior to coating as described in Collins et al. U.S. Pat. No.

2,9l2,343. A series of coatings are prepared in which the silver coverage/coupler coverage ratio is varied by varying the coupler dispersion flow rate and the nonDlR-coupler/DlR coupler ratio is varied by coating at a constant flow rate separate coupler dispersion having the appropriate ratios. Samples of each coating are exposed on an intensity scale sensitometer and processed through the Eastman Color Print Process, at 75 F. and a development time of 8 minutes with the following results.

14 image dye; and, said development inhibitor-releasing coupler has a monothio group in its coupling position which, upon reaction with oxidized primary aromatic amine color-developing agent, forms a diffusible mercaptan which inhibits development.

3. The method of claim 1 wherein each of said couplers are selected from the group consisting of an open-chain ketomethylene coupler radical; a S-pyrazolone coupler radical; and, a phenolic coupler radical.

Coatings 4-8 demonstrate the good uniformity in contrast obtained in accordance with this invention.

4. The method of in claim 3 wherein each of said couplers has one of the following structural formulas:

EXAMPLE 3 Formula I 0 H A photographic element of the type described above 15 R L prepared and coated in which the blue-sensitive emulsion and the yellow dye-forming coupler dispersion are mixed just prior 1 to coating as described in Collins et al. US. Pat. No. 2,912,343. A series of coatings is prepared in which the silver coverage/coupler coverage ratio is varied by varying the coupler dispersion flow rate and the nonDlR-coupler/DlR-coupler ratio is varied by coating at a constant flow rate separate 1 n R coupler dispersion having the appropriate ratios. Samples of Immula H T each coating were exposed on an intensity scale sensitometer Rs-N H l p and processed through the Eastman Co or rint Process, at cic F. and a development time of 8 minutes with the following ll results. 2

Coupler/ Percent silver Coupler variation Ag, ratio, in yellow Coating Number rug/ft. percent A, rngJft. B, mgJft. contrast Control 2.0 Control 80 -10 81 1.8 -1.9 so 20 72 1.6 -1.9 80 Control 90 2.0 Control 30 -10 Q1 2.5 -4.5

l:lighco ntrast uniformity s apparent in coatings 4, 5 and 6 50 Formula In on which maintain constant ratios of image coupler to DlR-coupler 1113* R10 When colored couplers D and G are omitted from examples 1 and 2, similar results are obtained with highly uniform con- R g Rn trast being exhibited throughout the emulsion layers. 5 5

The invention has been described in detail with particular L reference to certain preferred embodiments thereof, but it will be understood that variations and modifications can be effected within the spirit and scope of the invention as described hereinabove and as defined in the appended claims.

We claim:

1. A method for avoiding substantial differences in image contrast within a photographic element, said differences being attributable to uncontrolled variations in the ratio of incorporated image-forming coupler-to-silver halide in a photographic emulsion layer of said element, the improvement com prising introducing a development inhibitor-releasing coupler and at least one other coupler separately or in admixture at a controlled rate to effect an essentially constant ratio of development inhibitor-releasing coupler-toother coupler into a silver halide emulsion, admixing and coating the resulting composition onto a support.

2. The method of claim 1 wherein said photographic imageforming coupler, upon reaction with oxidized primary aromatic amine color developing agent, forms nondiffusible halogen and alkoxy; R and R when taken together, represents the atoms required to complete a benzo group, and

a. a member selected from the group consisting of hydrogen, halogen, a thiocyano group, an acyloxy group, an aryloxy group, a cyclooxy group, and, when said R and R represent the atoms to complete a benzo group, Y represents any of the foregoing groups given for Y and Y except aryloxy, and can in addition represent a cycloimido group, to complete said photographic image forming coupler; and,

b. a monothio group selected from an orthoamino substituted arylmonothio group; and, a heterocyclic radical containing at least one hetero atom selected from oxygen, sulfur and nitrogen, to complete said third coupler.

6. The method of claim 5 wherein said Y Y and Y each represents a heterocyclic monothio radical containing from one to four hetero nitrogen atoms, to complete said development inhibitor-releasing coupler.

7. The method of claim 6 wherein said Y,, Y and Y each represents a member selected from the group consisting of: a

2 nitrophenylthio group; a Z-aminophenylthio group a S "H050 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent N%i Dated January 4, 1972 Reid J. O'Connell and John H. VanCampen Inventor-(s) It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 3 line 35, delete entire line.

Column 4 line 33, replace "al.," with -fluorine.

Column 5 line 1 after "pivalyl-fiL insert line 2 after "phenylcarbamyl" insert line 41, replace "benzamidoih" with --benzamid9 line 12, after "l-(2' insert l'-; line U3, after ,"benzamido" insert a bracket --7-; line U 1 after "l:(2 insert l line Ml after fi delete "b" and insert a hyphen line 1 1, after "2' insert l'--;

line 16, after "l(2'," insert 5'-; line U8, after "l-(2' insert l',6'; line 50, after "l-(2' insert -5'- line 50, replace 1' with U line 51, replace "benzamidoih" with --benzamid o Column 6 line 3 after "0 delete "1'';

lines 4 and 5, replace both lines with -tylphenoxy)- propionamido-H-thiocyano5pyrazolone; line 6 after "trichlorophenyl" insert a parenthesis Pa e l of I a es. L g p g UNITED STATES PATENT OFFICE CETIFICATE F COEC'HN Patent No. 3 Dated January 4 1972 Inventor) Reid J. O'Connell and John H. VanCampen It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 6 line 18, after "1" insert a hyphen -5 line 20, after "diphenylethersulfonamido-" insert -l-naphthol;

line ?5, replace entire line with -2-[ c1l-( 1 '-tert butylphenoxy)propionylamino/phenol-;

line 38, after "2" delete "60" and insert line 4 after "2@& delete 5 (second occurrence) 5 line 52, after l"' j,nsert a hyphen line 52, after ."sulfonamido)" insert a hyphen line 55, delete "phenolic".

Column 7 line 8 after "-N-i" delete 147? and insert line 11 after 'NA;L delete 6;." (second occurrence) Column 8 line 9 after lcarboxyethyl" delete "U-sulfoethyl-"5 line 10, after "benzotriazolyl" insert -U-sulfoethyl-2- benzotriazolyl,;

line 25, after JR-2" insert a hyphen line 26, after "L .2 3" insert a hyphen and then a bracket line 29 delete "stearamido"; line 32, after "benzolyl" delete line 38, after "benzotriazolyl)" insert a hyphen Page 2 of 1 pages.

zgz gy UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3 3 ,373 Dated January 1972 Inventor) Reid J O'Connell and John H. VanCampen It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 8 line 39 replace entire line with --chloro-5' Q\ (3-pentadecyl-U-sulline 17, after "trichlorophenyl)3" insert a hyphen line 6U, after "propionamido/" insert a hyphen Column 9 line 1 after "tetrazolythio)-" insert 5pyrazolone;

lines 12 and 13, after "acetamido" (line 12) delete "3- a; (2, 1-di-t-amylphenoxy)acetamido"5 line 17, replace "pentacecyl" with -pentadecyl.

Column 10, line 23, after "group," insert -which render-.

Column 11 line 23 after "N-p insert a hyphen Column 13, Example 2, the table, replace the number "7" on last line Of Col U with 85.

Column 1 1, Formulae II and III, replace both formulae with Formula II R n \Y O 2 ormula III R lo Page 3 of 4 pages. 1. 3 I .l

v and that said Letters Patent are hereby corrected as shown below:

UNITED STATES PATENT GF CE QETIFICAT r CEQTIN Patent No. 3, 3 ,373 Dated January 4, 1972 inventor) Reid J. O'Connell and John H. VanCampen PAGE 4 It is certified that error appears in the above-identified patent Column 15, Formulae II and III, replace both formulae with -Formula II Formula III R 1o Column 16, line 15, after "groupg" insert -an orthonitro-substituted arylmonothio group;--.

Signed and sealed this 20th day of June 1972.

(SEAL) Attesjt:

L. EDwAsoMeFLETcHERJR, ROBERT GOTTSCHALK Attestlng Officer Commissioner of Patents 

2. The method of claim 1 wherein said photographic image-forming coupler, upon reaction with oxidized primary aromatic amine color developing agent, forms nondiffusible image dye; and, said development inhibitor-releasing coupler has a monothio group in its coupling position which, upon reaction with oxidized primary aromatic amine color-developing agent, forms a diffusible mercaptan which inhibits development.
 3. The method of claim 1 wherein each of said couplers are selected from the group consisting of an open-chain ketomethylene coupler radical; a 5-pyrazolone coupler radical; and, a phenolic coupler radical.
 4. The method of in claim 3 wherein each of said couplers has one of the following structural formulas:
 5. The method of claim 3 wherein each of said couplers has one of the following structural formulas:
 6. The method of claim 5 wherein said Y1, Y2 and Y3 each represents a heterocyclic monothio radical containing from one to four hetero nitrogen atoms, to complete said development inhibitor-releasing coupler.
 7. The method of claim 6 wherein said Y1, Y2 and Y3 each represents a member selected from the group consisting of: a 2-nitrophenylthio group; a 2-aminophenylthio group; a 5-tetrazolylthio group; a 2-benzothiazolylthio group; and a 5-phenyl-1,3,4-oxadiazolylthio group, to complete said development inhibitor-releasing coupler. 